[Therion] 3d file wall models - scrap connections

[Stacho Mudrak]

Wookey wrote:
> I very much like the 3d map output into survex .3d format. However it
> does seem to have a problem at joins. It all looks lovely in plan
> view, but as soon as you look sideways you will see that there is
> often a vertical offset in the lines at the join.

Yes, but doing it correctly is really a great problem. Currently, we 
process joins in 2D, and even there it does not work very well :( If you 
do not draw sketches in scale, therion is not able to morph scraps 
correctly. Doing morphing in 3D would be nice, but to do it, we need to 
redesign morphing codes completely. We have started to work on this, but 
it will definitely take some time.

> I can see that there _might_ be a pitch at the pont of the join, but
> normally a smooth transition in the vertical as well as horizontal
> plane is desired.

Agree.

> How are the vertical co-ordoinates at the ends of
> scraps determined, and is it possible to msake sure they 'join' (have
> the same co-ordinates) both vertically as well as horizontally?

Coordinates are determined by interpolation from stations in scrap. 
Currently we use "inverse distance to a power" as a weighting function.

> option to say 'add vertical lines to complete join' would be useful
> for cases where there is a step height change (e.g the connection
> between menagerie_s4 and terikan.reifticious_s1). But I'm not quite
> sure how/where this might be done. If it is hard, then joining
> everything up would be much better than it is now.

We will see, but "step-by-step" :)

In the near future, I would like to finish new 3D viewer (this has 
priority #1), then we would like to add support of geographical 
coordinate systems (UTM and others) directly in therion and then, we can 
start improving morphing functions.

> See http://wookware.org/mulu/MuluWalls.3d, then look at it on a bit of
> a tilt. 

BTW, do you present also these 3D's, that you want them to look 
smoother? I am wondering :) I need smooth joins in 3D just for model 
generation.

S.